From: Alban Gruin Date: Thu, 31 Jan 2019 20:37:52 GMT Subject: Re: [PATCH v6 07/16] sequencer: refactor sequencer_add_exec_commands() to work on a todo_list Message-ID: In-Reply-To: <434cf0f7-1df6-7966-b460-e69e8f8b5e99@talktalk.net> Hi Phillip, Le 31/01/2019 à 15:30, Phillip Wood a écrit : > Hi Alban > > On 29/01/2019 15:01, Alban Gruin wrote: >> This refactors sequencer_add_exec_commands() to work on a todo_list to >> avoid redundant reads and writes to the disk. >> >> Instead of inserting the `exec' commands between the other commands and >> re-parsing the buffer at the end, they are appended to the buffer once, >> and a new list of items is created.  Items from the old list are copied >> across and new `exec' items are appended when necessary.  This >> eliminates the need to reparse the buffer, but this also means we have >> to use todo_list_write_to_disk() to write the file. >> >> todo_list_add_exec_commands() and sequencer_add_exec_commands() are >> modified to take a string list instead of a string -- one item for each >> command.  This makes it easier to insert a new command to the todo list >> for each command to execute. >> >> sequencer_add_exec_commands() still reads the todo list from the disk, >> as it is needed by rebase -p. >> >> complete_action() still uses sequencer_add_exec_commands() for now. >> This will be changed in a future commit. >> >> Signed-off-by: Alban Gruin >> --- >>  builtin/rebase--interactive.c |  15 +++-- >>  sequencer.c                   | 110 +++++++++++++++++++++------------- >>  sequencer.h                   |   5 +- >>  3 files changed, 82 insertions(+), 48 deletions(-) >> >> diff --git a/builtin/rebase--interactive.c >> b/builtin/rebase--interactive.c >> index df19ccaeb9..53056ee713 100644 >> --- a/builtin/rebase--interactive.c >> +++ b/builtin/rebase--interactive.c >> @@ -65,7 +65,7 @@ static int do_interactive_rebase(struct replay_opts >> *opts, unsigned flags, >>                   const char *onto, const char *onto_name, >>                   const char *squash_onto, const char *head_name, >>                   const char *restrict_revision, char *raw_strategies, >> -                 const char *cmd, unsigned autosquash) >> +                 struct string_list *commands, unsigned autosquash) >>  { >>      int ret; >>      const char *head_hash = NULL; >> @@ -116,7 +116,7 @@ static int do_interactive_rebase(struct >> replay_opts *opts, unsigned flags, >>          discard_cache(); >>          ret = complete_action(the_repository, opts, flags, >>                        shortrevisions, onto_name, onto, >> -                      head_hash, cmd, autosquash); >> +                      head_hash, commands, autosquash); >>      } >>   >>      free(revisions); >> @@ -139,6 +139,7 @@ int cmd_rebase__interactive(int argc, const char >> **argv, const char *prefix) >>      const char *onto = NULL, *onto_name = NULL, *restrict_revision = >> NULL, >>          *squash_onto = NULL, *upstream = NULL, *head_name = NULL, >>          *switch_to = NULL, *cmd = NULL; >> +    struct string_list commands = STRING_LIST_INIT_DUP; >>      char *raw_strategies = NULL; >>      enum { >>          NONE = 0, CONTINUE, SKIP, EDIT_TODO, SHOW_CURRENT_PATCH, >> @@ -221,6 +222,12 @@ int cmd_rebase__interactive(int argc, const char >> **argv, const char *prefix) >>          warning(_("--[no-]rebase-cousins has no effect without " >>                "--rebase-merges")); >>   >> +    if (cmd && *cmd) { >> +        string_list_split(&commands, cmd, '\n', -1); > > This whole splitting and later skipping 'exec ' is a bit of a shame - it > would be much nicer if we could just have one exec command per -x option > but I think that is outside the scope of this series (If I have time I'd > like to look at calling do_interactive_rebase() directly from > builtin/rebase.c without forking rebase--interactive). > Yes, I completely agree with you. I thought to do this in preparation to drop rebase -r. >> +        if (strlen(commands.items[commands.nr - 1].string) == 0) > > I'd be tempted just to test the string using !* rather than calling > strlen. > Right. I’m still not used to this pattern. > Also is there ever a case where the last string isn't empty? I don’t think so. When rebase.c prepares the arguments for rebase--interactive, it always add a newline at the end[1]. Do you want me to drop this check? >> +            --commands.nr; >> +    } >> + >>      switch (command) { >>      case NONE: >>          if (!onto && !upstream) >> @@ -228,7 +235,7 @@ int cmd_rebase__interactive(int argc, const char >> **argv, const char *prefix) >>   >>          ret = do_interactive_rebase(&opts, flags, switch_to, >> upstream, onto, >>                          onto_name, squash_onto, head_name, >> restrict_revision, >> -                        raw_strategies, cmd, autosquash); >> +                        raw_strategies, &commands, autosquash); >>          break; >>      case SKIP: { >>          struct string_list merge_rr = STRING_LIST_INIT_DUP; >> @@ -262,7 +269,7 @@ int cmd_rebase__interactive(int argc, const char >> **argv, const char *prefix) >>          ret = rearrange_squash(the_repository); >>          break; >>      case ADD_EXEC: >> -        ret = sequencer_add_exec_commands(the_repository, cmd); >> +        ret = sequencer_add_exec_commands(the_repository, &commands); >>          break; >>      default: >>          BUG("invalid command '%d'", command); >> diff --git a/sequencer.c b/sequencer.c >> index 266f80d704..3a90b419d7 100644 >> --- a/sequencer.c >> +++ b/sequencer.c >> @@ -4446,25 +4446,27 @@ int sequencer_make_script(struct repository >> *r, FILE *out, >>      return 0; >>  } >>   >> -/* >> - * Add commands after pick and (series of) squash/fixup commands >> - * in the todo list. >> - */ >> -int sequencer_add_exec_commands(struct repository *r, >> -                const char *commands) >> +static void todo_list_add_exec_commands(struct todo_list *todo_list, >> +                    struct string_list *commands) >>  { >> -    const char *todo_file = rebase_path_todo(); >> -    struct todo_list todo_list = TODO_LIST_INIT; >> -    struct strbuf *buf = &todo_list.buf; >> -    size_t offset = 0, commands_len = strlen(commands); >> -    int i, insert; >> +    struct strbuf *buf = &todo_list->buf; >> +    size_t base_offset = buf->len; >> +    int i, insert, nr = 0, alloc = 0; >> +    struct todo_item *items = NULL, *base_items = NULL; >>   >> -    if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0) >> -        return error(_("could not read '%s'."), todo_file); >> +    base_items = xcalloc(commands->nr, sizeof(struct todo_item)); >> +    for (i = 0; i < commands->nr; ++i) { >> +        size_t command_len = strlen(commands->items[i].string); >>   >> -    if (todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list)) { >> -        todo_list_release(&todo_list); >> -        return error(_("unusable todo list: '%s'"), todo_file); >> +        strbuf_addstr(buf, commands->items[i].string); >> +        strbuf_addch(buf, '\n'); >> + >> +        base_items[i].command = TODO_EXEC; >> +        base_items[i].offset_in_buf = base_offset; >> +        base_items[i].arg_offset = base_offset + strlen("exec "); >> +        base_items[i].arg_len = command_len - strlen("exec "); >> + >> +        base_offset += command_len + 1; >>      } >>   >>      /* >> @@ -4473,38 +4475,62 @@ int sequencer_add_exec_commands(struct >> repository *r, >>       * those chains if there are any. >>       */ >>      insert = -1; >> -    for (i = 0; i < todo_list.nr; i++) { >> -        enum todo_command command = todo_list.items[i].command; >> - >> -        if (insert >= 0) { >> -            /* skip fixup/squash chains */ >> -            if (command == TODO_COMMENT) >> -                continue; >> -            else if (is_fixup(command)) { >> -                insert = i + 1; >> -                continue; >> -            } >> -            strbuf_insert(buf, >> -                      todo_list.items[insert].offset_in_buf + >> -                      offset, commands, commands_len); > > In a todo list that looks like > pick abc message > #pick cde empty commit > This inserts the exec command for the first pick above the commented out > pick. I think your translation puts it below the commented out pick as > it ignores the value of insert. I think it's probably easiest to add an > INSERT_ARRAY macro to insert it in the right place. An alternative might > be to track the last insert position and only copy commands across when > there is another exec to insert but that might get complicated in cases > such as > > pick abc message > #squash cde squash! message //empty commit for rewording > fixup 123 fixup! message > #pick 456 empty commit > I could do this with MOVE_ARRAY(), no? > Best Wishes > > Phillip > [1] https://github.com/git/git/blob/master/builtin/rebase.c#L1182-L1191 Cheers, Alban